 Roof cement, nail it. And really, they are because of their position on the roof more prone to wind damage and stuff like that. Well, and that's why you want to make your, from your prevailing wind, you really should start those shingles going the other way so that it doesn't, can't get lift, it can't get up underneath them. That's where the problem lies because a lot of times people will put them face into the west and that's the worst thing you can do.